ElasticSearch, appending value to field, but check if field exists first, if not create field then append

I’m trying to dynamically add a new array type field to documents as they need it, If the field exists already (ie, someone else already added an item to the array) then append my item. If it doesn’t exist, I need it to create the field then append my item.

Currently I can only append if I first create the field but the way I’ve written it overwrites existing field values if present.

# Create the field, not ideal as it wipes the field if it existed already

        es.update(
            index='index_name',
            id='doc_id_987324bhashjgbasf',
            body={"doc": {
                'notes': []}})

# Append my value
    es.update(index='index_name', id='doc_id_987324bhashjgbasf',
              body={
                  "script": {
                      "source": "ctx._source.notes.addAll(params.new_note)",
                      "lang": "painless",
                      "params": {
                          "new_note": [{'note': 'Hello I am a note', 'user':'Ari'}]
                      }
                  }
              })

Ideally the process I’d like is

Check if field ‘notes’ exists
If it exists, append new value with existing values
If it doesn’t exist, create field then append my value

Answer

logstash:

if [notes] {
    notes.add("NewItem");
} else {
   notes = new ArrayList();
   notes.add("NewItem");
}

elasticsearch:

"script": "if (ctx._source.containsKey("notes")) {ctx._source.notes += value;} else {ctx._source.notes = [value]}"

Advertisement

Answer